Switch clearing system
CA 2273045 C · Owner: Lepage, Michel A. · Inventors: Sumpton, Danny M.; Lepage, Michel A.
Overview
Its claims, description and drawings are in the Canadian Patents Database.
Open the CIPO recordAbstract From the Canadian patent
An air blowing system for use in keeping railroad track switches clear of snow utilizes flexible tubes preferebly of rubber or plastic, located transversely beneath the main tracks and connecting with resilient nozzles to direct a high flow of air in the direction of the track switch points. The system may include resilient ducts conveying air in protective relation with the switch control rods extending laterally beneath the track. The rod protective air discharge may be by way of a louvered cross-tube extending parallel with the rods, to discharge air laterally of the rods or one or more nozzles discharging air longitudinally of the rods.
Read the whole patent
Listed from its CIPO record in Patent Yard's archive of Canadian patents past their term. Its claims, description and drawings are in the CIPO record and on Google Patents, and the Claude kit works from them.
Why it's free to use
- Filed May 26, 1999 and granted October 28, 2003. A Canadian patent filed from October 1, 1989 lasts 20 years from filing, so its term ended May 26, 2019.
- A certificate of supplementary protection adds at most two years for a drug, so even that would have ended by May 26, 2021.
- We check Canadian rights only. A patent in its family in another country could still be in force: check its family on Google Patents.
Timeline
Timeline From CIPO dates
Sources & verification
Official CIPO records
Everything on this page comes from the CIPO record linked above. Contains information licensed under the Open Government Licence – Canada.